Module com.aoapps.encoding

Package com.aoapps.encoding

Class ShValidator

java.lang.Object

java.io.Writer

java.io.FilterWriter

com.aoapps.encoding.MediaValidator

com.aoapps.encoding.ShValidator

All Implemented Interfaces:

ValidMediaFilter, ValidMediaInput, ValidMediaOutput, NoClose, Closeable, Flushable, Appendable, AutoCloseable

@ThreadSafe
public final class ShValidator
extends MediaValidator

Although shell scripts can potentially parse and execute with lots of unprintable and binary values, we are validating a more strict subset of characters that are generally text editor and copy/paste friendly. We will consider shell scripts relying on unusual characters, even if technically supported, to be invalid. This choice is made to help isolate bugs and accidental conflations of data and code.

This implementation is based on Bash, but it is expected to be compatible with other shells.

Author:

AO Industries, Inc.

Field Summary

Fields inherited from class java.io.FilterWriter

out

Fields inherited from class java.io.Writer

lock

Method Summary

Modifier and Type	Method	Description
ShValidator	append(char c)	The default implementation of this append method in Writer calls the write(int) method for backward-compatibility.
ShValidator	append(CharSequence csq)	The default implementation of this append method in Writer converts to a String for backward-compatibility.
ShValidator	append(CharSequence csq, int start, int end)	The default implementation of this append method in Writer converts to a String for backward-compatibility.
boolean	canSkipValidation(MediaType outputType)	Checks if validation may be skipped when the characters being written to this validator is already known to be valid with the given media type.
static void	checkCharacter(char c)	Checks one character, throws InvalidCharacterException if invalid.
static void	checkCharacters(char[] cbuf, int off, int len)	Checks a set of characters, throws InvalidCharacterException if invalid.
static void	checkCharacters(CharSequence str, int start, int end)	Checks a set of characters, throws InvalidCharacterException if invalid.
MediaType	getValidMediaInputType()	Gets the input type.
boolean	isValidatingMediaInputType(MediaType inputType)	Checks if this is validating the provided type, which allows one validator to be substituted in place of another.
void	write(char[] cbuf, int off, int len)
void	write(int c)
void	write(String str, int off, int len)

Methods inherited from class com.aoapps.encoding.MediaValidator

getMediaValidator, getOut, getValidMediaOutputType, isBuffered, isNoClose, validate

Methods inherited from class java.io.FilterWriter

close, flush

Methods inherited from class java.io.Writer

nullWriter, write, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.aoapps.lang.io.NoClose

close

Method Details

checkCharacter

public static void checkCharacter(char c)
                           throws InvalidCharacterException

Checks one character, throws InvalidCharacterException if invalid.

See Advanced Bash-Scripting Guide: Special Characters: Control Characters.

Throws:

InvalidCharacterException

checkCharacters

public static void checkCharacters(char[] cbuf,
 int off,
 int len)
                            throws InvalidCharacterException

Checks a set of characters, throws InvalidCharacterException if invalid.

See Advanced Bash-Scripting Guide: Special Characters: Control Characters.

Throws:

InvalidCharacterException

checkCharacters

public static void checkCharacters(CharSequence str,
 int start,
 int end)
                            throws InvalidCharacterException

Checks a set of characters, throws InvalidCharacterException if invalid.

See Advanced Bash-Scripting Guide: Special Characters: Control Characters.

Throws:

InvalidCharacterException

getValidMediaInputType

public MediaType getValidMediaInputType()

Description copied from interface: ValidMediaInput

Gets the input type.

isValidatingMediaInputType

public boolean isValidatingMediaInputType(MediaType inputType)

Description copied from interface: ValidMediaInput

Checks if this is validating the provided type, which allows one validator to be substituted in place of another. This is acceptable when this validator is equal to, or more strict, than the given inputType.

Please note that this validator only needs to block invalid characters for inputType. This validator does not need to let through all characters, just block the invalid. This is a one-way optimization.

This is almost the inverse operation of ValidMediaInput.isValidatingMediaInputType(com.aoapps.encoding.MediaType), with the exception of characters only invalid due to nested encodings.

Returns:

true when this validator will throw exceptions on all invalid characters from the given inputType

See Also:

• ValidMediaInput.canSkipValidation(com.aoapps.encoding.MediaType)

canSkipValidation

public boolean canSkipValidation(MediaType outputType)

Description copied from interface: ValidMediaInput

Checks if validation may be skipped when the characters being written to this validator is already known to be valid with the given media type. This may be done when every valid character for the given media type is also valid within this validator.

This is almost the inverse operation of ValidMediaInput.isValidatingMediaInputType(com.aoapps.encoding.MediaType), with the exception of characters only invalid due to nested encodings.

Returns:

true when all valid characters of the given outputType are also valid on this validator

See Also:

• ValidMediaInput.isValidatingMediaInputType(com.aoapps.encoding.MediaType)

write

public void write(int c)
           throws IOException

Overrides:

write in class FilterWriter

Throws:

IOException

write

public void write(char[] cbuf,
 int off,
 int len)
           throws IOException

Overrides:

write in class FilterWriter

Throws:

IOException

write

public void write(String str,
 int off,
 int len)
           throws IOException

Overrides:

write in class FilterWriter

Throws:

IOException

append

public ShValidator append(CharSequence csq)
                   throws IOException

Description copied from class: MediaValidator

The default implementation of this append method in Writer converts to a String for backward-compatibility. This passes the append directly to the wrapped Writer.

Specified by:

append in interface Appendable

Overrides:

append in class MediaValidator

Throws:

IOException

append

public ShValidator append(CharSequence csq,
 int start,
 int end)
                   throws IOException

Description copied from class: MediaValidator

The default implementation of this append method in Writer converts to a String for backward-compatibility. This passes the append directly to the wrapped Writer.

Specified by:

append in interface Appendable

Overrides:

append in class MediaValidator

Throws:

IOException

append

public ShValidator append(char c)
                   throws IOException

Description copied from class: MediaValidator

The default implementation of this append method in Writer calls the write(int) method for backward-compatibility. This passes the append directly to the wrapped Writer.

Specified by:

append in interface Appendable

Overrides:

append in class MediaValidator

Throws:

IOException